Is the regular water pump casting 839403? I have looked at those same parts books and the confusing part is that GM part 3836084 states for 53-55 Pass/Comm (except HT). GM part 3836223 states 54-55 Comm with HT (with trans cooler). I believe the trans cooler was only on 1 ton and 1.5 ton trucks. Hopefully someone has a stock water pump on their Hydra-Matic that can shed some light. Thanks for your input.
